I re-read nikala's fine article on Mioko Yamaguchi's （山口美央子）"Tsukihime"（月姫）and took a listen to it and the other song, "Koi no Shunkan" (恋の春感...both from 1983), which inspired me to take a look through YouTube for any other of the singer's material.
And then I discovered this happy, shiny piece. Compared to Yamaguchi's technopoppy 80s Akiko Yano-ish approach to the two songs that nikala covered, "Kaze ni Dakarete" (Embraced by the Wind) is far more in the City Pop genre. It was a track from her 1981 album, "Nirvana", and the song came at me like a sea breeze into my resort hotel suite. I'd say that "Kaze ni Dakarete" occupies that genre within City Pop known as Resort Pop.
Nikala also pointed out that there isn't a whole lot of information on Yamaguchi, Japanese or English. However, I was able to find a Japanese page which gives a review of all of albums between 1980 and 1985. For the paragraph on her second album, "Nirvana", the author states that "Kaze ni Dakarete" sounds like something that a young Mariya Takeuchi（竹内まりや）would have tackled as an example of Light & Mellow AOR. I can agree but I think two other singers who are even closer in sound are Takako Mamiya（間宮貴子）and Yurie Kokubu（国分友里恵） from the same time period (check the Labels to the right).
I'm sure Yamaguchi had her reasons for going solely into songwriting from the mid-80s, but from this song and the two tracks from "Tsukihime" the album, I think it's a bit of a pity that she completely gave up on singing.